This invention is generally concerned with postage metering apparatus including means for guarding against printing a postage value without accounting therefor, and more particularly with postage metering apparatus including means for disabling an operation thereof upon accounting for a predetermined number of zero postage value requests.
In the course of conducting a search concerning the subject matter of the present invention, the following references were found: U.S. Pat. No. 3,702,097 for Anti-Hammer Apparatus For Powered Imprinters, issued Nov. 7, 1972 to St. Jean; U.S. Pat. No. 4,253,015 for an Electronic Postage Meter Having An Accounting System Independent Of Power Failure, issued Feb. 24, 1981 to Eckert et al.; and, U.S. Pat. No. 5,307,280 for a Franking Machine, issued Apr. 26, 1994 to Haug.
Of the aforesaid references the '015 Patent, issued to Eckert et al., is relevant in that it describes conventional electronic postage metering apparatus, comprising, a rotary printing drum having mounted therein a plurality of print wheels, structure for feeding a sheet to the drum, structure for selectively rotating the print wheels to a postage value to be printed on a sheet fed to the drum, and prior art structure for causing the postage value to be accounted for before being printed. For accounting purposes, the postage metering apparatus includes a microprocessor having structure which is programmed for accounting for the selected postage value and thereafter releasing an interposer, which is normally disposed in blocking relationship with the printing drum, to permit a single revolution of the drum for printing the selected postage value.
In addition, the '280 Patent issued to Haug is relevant in that it describes a franking machine which includes a casing and a main memory for storing a total postage value available for printing, and includes prior art structure for guarding against tampering with the total postage value when the casing is open. To that end, the franking machine includes a central processing unit (CPU) having a service program which is implemented when the casing is opened for transferring the total postage value from a main memory to an inaccessible backup memory, thereby changing the stored value in the main memory to a zero value. Although not a model of clarity, a fair reading of the '280 Patent indicates that while the casing is open, the program causes polling to occur, for periodically sequentially checking the postage value stored in the main memory and the settings of the print wheels, to respectively determine whether the memory has stored therein more than a zero value and whether the print wheel settings are set to more than a zero value, and, if either of such events occur, the program causes such values to be changed to zero values. Accordingly, while the casing is open, the program remedies tampering with the main memory and the print wheel settings to thereby prevent the subsequent printing of an unaccounted for postage value. On the other hand, when the casing is thereafter closed, although the program causes the total postage value to be restored to the main memory, no program processing occurs to either thwart, guard against or remedy the printing of any unaccounted for postage value.
Thus, the references are silent concerning the provision of structure for disabling an operation or preventing any particular use of postage metering apparatus, for example, of the type described in the '015 Patent issued to Eckert et al, which has been purposely physically damaged to immobilize the print wheels so that with each revolution of the printing drum a non-zero postage value is printed, although the microprocessor controlled accounting structure accounts for the selection of a zero postage value to be printed and releases the interposer to permit a single revolution of the damaged drum.
Moreover, the references are silent concerning the provision of structure for preventing a User of postage metering apparatus who processes a batch of letters, from improperly using the postage metering apparatus for printing zero postage values on a small percentage, say up to 15%, of the batch of letters, with the thought in mind of taking a chance that Postal Service employees who spot check batches of letters will not discover the inclusion of numerous letters having printed thereon a zero postage value.
Accordingly, an object of the invention is to provide postage metering apparatus including means for guarding against printing a postage value without accounting therefor; and another object is to provide postage metering apparatus including means for disabling an operation or preventing a use thereof upon accounting for a predetermined number of requests for printing a zero postage value,